Tethys Ocean Floor
Tethys Ocean Floor
Endless and eternal are two words most often associated with the sea. Yet, like so many structures on Earth, the vast oceans of the world exist in a constant state of change, and even after hundreds of millions of years, they sometimes disappear leaving only the smallest trace of their passing.
The Tethys Ocean was an ancient sea that emerged out of Pangea in the Triassic period. For millions of years, it was filled with aquatic animals like ammonites, plesiosaurs, and ichthyosaurs. As tectonic plates crashed against each other though, the bedrock of the ocean was lifted thousands of feet above sea level. This brought about the end of the Tethys and created many mountain ranges within Eurasia.
This specimen is a fragment of oceanic slate from the prehistoric Tethys seafloor. It was recovered from the Himalayas along the banks of the Gandaki River (Kali) in Nepal. Composed primarily of ammonite and belemnite fossils, this layer of dark shale was lifted tens of thousands of feet above sea level as the Indian subcontinent crashed into Asia.
📸 Dark Ocean Floor Shale
A Prehistoric Ocean
We tend to think of our planet's surface as endless and eternal — the story of the Tethys Ocean reminds us it's anything but.
Millions of years ago, during the Mesozoic era, the Tethys Ocean formed in an opening of the supercontinent Pangea. This seaway was home to many forms of life throughout the Age of Dinosaurs. Eventually, a collision between two tectonic plates would change everything.
These plates crashed into each other, resulting in an angled overlapping. Though this process was slow at first, the plates continued to shift. Over time, the sea floor rose higher and higher as the two tectonic plates pushed each other upward. This uplift resulted in one of the largest mountain-making events in history — the Alps, the Carpathians, and even the Himalayas all come from what was once the Tethys Sea. Today, we find ocean fossils among those peaks, an incredible reminder of our planet's shifting surface.
This specimen is a piece of dark shale from the Tethys Ocean recovered from the Himalayas along the banks of the Gandaki River. This geologic layer is quite far from any oceans today, an incredible reminder of just how drastically our planet can change.
Each ocean floor piece is hand-cut by our technicians and is protected by an acrylic specimen jar. The jar is enclosed inside a classic, glass-topped riker display case that measures 4"x3"x1". A small information card is enclosed that also serves as the certificate of authenticity.
Additionally, we also have a select amount of fossils from the Tethys layer available for purchase as single items in the collection below.
INITIAL FORMATION: TRIASSIC PERIOD (C. 250,000,000 YEARS AGO)
MORE ABOUT THE TETHYS OCEAN
"Modern geology permits us to follow the first outlines of the history of a great ocean which once stretched across part of Eurasia. The folded and crumpled deposits of this ocean stand forth to heaven in Tibet, Himalaya, and the Alps. This ocean we designate by the name “Tethys,” after the sister and consort of Oceanus. The latest successor to the Tethyan Sea is the present Mediterranean." ~ Eduard Suess, Austrian Geologist, "Are Great Ocean Depths Permanent" (1893)
The Birth of an Ocean
It’s easy to see the geography of our planet as fixed and immutable, our continents and oceans unchanging. This is hardly the case on the geologic scale. Earth's landmasses and seas are not static, they’re an ever changing tapestry propelled by massive tectonic plates shifting below our feet.
250 million years ago in the Mesozoic era, the continental plates were joined together like puzzle pieces to form the Pangea supercontinent — but Pangea was changing. From within, the mighty Tethys Ocean was being born.
Named for a sea goddess from Greek mythology, the Tethys Ocean took many forms over the eons, expanding and contracting as the continents shifted around it. At the beginning of the Mesozoic Era, the Tethys Ocean was bound by the great Panthalassan Ocean within the cradle of the supercontinent Pangaea. During the Jurassic Period, the shifting continents compressed the Tethys to form an equatorial seaway stretching from today's Caribbean Islands to what is now the Himalayas.
📸 The Tethys Ocean on Late Jurassic Earth (From Encyclopaedia Britannica)
This Jurassic seaway split the land and allowed the continents to take the shapes we know today. The Tethys formed a barrier between the diverging Americas, Eurasia and Africa. While reduced in size, The Tethys continued to have an enormous impact on its surrounding environment, acting as a kind of oceanic superhighway and carrying floral and faunal species across the world.
With the disaster of the Triassic-Jurassic extinction event, many species of animals went extinct, with marine life particularly devastated, owing to ocean acidification. Ironically, this cataclysm made the Tethys the perfect breeding ground for life: it had a new environment makeup, a new chemical balance and plenty of uninhabited room, making it an ideal spot for new species to evolve and replace the old.
Thanks to tropical conditions, life flourished. At the height of the Tethys, you could find small creatures like plankton and sea snails, a sudden burst of new ammonites, and the even marine reptiles like ichthyosaurs and plesiosaurs hunting for prey.
📸 A belemnite fossil encased in Tethys ocean material
Raising the Seas
Paradoxically, this abundance of life (plankton specifically) created dangerously low oxygen levels, and parts of the Tethys became stagnant and muddy. Lucky for us, these were the perfect conditions for dying animals to be preserved as fossils.
The end of the Tethys came in stages with the collisions of the African, Arabian, and Indian tectonic plates with Eurasia, which mainly commenced in the Paleocene and Eocene. This convergence initiated the planet’s mightiest modern mountain-building episodes: the Alpine (or Alpide) orogeny, which has thrown up mountain ranges from Western Europe to Southeast Asia, including such uplifts as the Pyrenees, the Alps, the Caucasus, the Zagros, the Hindu Kush, the Karakorum, and the Himalayas.
The ocean floor which was once the Tethys rose high into the air, becoming material for the incredible mountain ranges across Eurasia. As a side effect of this uplift event, the ocean fossils that had been buried for millions of years now found themselves at some of the highest peaks in the world. Today, ammonites, belemnites, and even ichthyosaur fossils can be found buried in the side of mountains.
Front of the Specimen Card
Back of the Specimen Card
Further Reading
Stow, D. A. Vanished Ocean : How Tethys Reshaped the World. Oxford University Press, 2010.
(1) Berra, Fabrizio & Lucia Angiolini. “The Evolution of the Tethys Region Throughout the Phanerozoic: A Brief Tectonic Reconstruction.” In Petroleum Systems of the Tethyan Region, edited by L. Marlow, et al., AAPG Memoir 106, 2014, pp. 1-27.
(2) Ocean: The Definitive Visual Guide. DK Publishing, 2014.
(3) Quinn, Joyce A. & Susan L. Woodward (eds.). Earth’s Landscape: An Encyclopedia of the World’s Geographic Features. ABC-CLIO, LLC, 2015.
(4) Tang, Carol M. “Tethys Sea.” Britannica, 2019. Web. 14 July 2019.
(5) Stow, Dorrik. Vanished Ocean: How Tethys Reshaped the World. Oxford University Press, 2010.
(6) Keppie, D. Fraser. “How the Closure of Paleo-Tethys & Tethys Oceans Controlled the Early Breakup of Pangaea.” Geology, vol. 43, no. 4, 2015, pp. 335-338.
(7) Hilgen, F.J., et al. “The Neogene Period.” In The Geologic Time Scale, edited by Felix M. Gradstein, et al., Elsevier, 2012, pp. 923-978.
(8) Gerhard, Lee C. & William E. Harrison. “Distribution of Oceans & Continents: A Geological Constraint on Global Climate Variability.” In Geological Perspectives of Global Climate Change, edited by Lee C. Gerhard, et al., AAPG Studies in Geology, 2001, pp. 35-49.
(9) Luyendyk, Bruce P. “Paleoceanography.” Britannica, 2019. Web. 14 July 2019.
(10) Celâl Şengör, A.M. & Saniye Atayman. The Permian Extinction & the Tethys: An Exercise in Global Geology. The Geological Society of America, 2009.
(11) Aktor, Mikael. “Grasping the Formless in Stones: The Petromorphic Gods of the Hindu Pañcāyatanapūjā.” In Aesthetic of Religion: A Connective Concept, edited by Alexandra K. Grieser & Jay Johnston, De Gruyter, 2017, pp. 59-73.
(12) Suess, Edward "Are Great Ocean Depths Permanent" 1893.
(13) Sakai, Harutaka. "Rifting of the Gondwanaland and uplifting of the Himalayas recorded in Mesozoic and Tertiary fluvial sediments in the Nepal Himalayas." Sedimentary facies in the active plate margin (1989): 723-732.
